MLA
Co., E. C. Kropp. When Shall We Three Meet Again? : Two African American Boys. 1908. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 72. https://digital.library.emory.edu/purl/764gmsbcds-cor.
APA, 6th edition
Co., E. C. K. (1908). When shall we three meet again? : two African American boys (Box 72) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/764gmsbcds-cor.
Chicago
Co., E. C. Kropp. “When Shall We Three Meet Again? : Two African American Boys.” Postcards. Robert Langmuir African American Photograph Collection, 1908. Box 72. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/764gmsbcds-cor.